Crystal Structure and Spectroscopic Analysis of Polyphenyl Quinoxaline with Hg(Ⅱ)

The interaction of Hg~(2+) with polyphenyl quinoxaline ligand 2,3,6,7,10,11-hexaphenyldipyrazino[2,3-f:2?,3?-h]quinoxaline(HPQ) was investigated, and a new complex(C_(49)H_(32)N_6Br_2Cl_2Hg) has been synthesized and characterized. It exhibits a 0D single-core structure,and adopts triclinic P 1 space group with a = 11.139(2), b = 13.429(3), c = 14.488(3) ?, α =76.10(3), β = 83.16(3), γ = 87.36(3)o, V = 2088.4(7) ?3, Z = 2, S = 1.056, F(000) = 1104, R = 0.0417 and w R = 0.0931(I 2σ(I)). Furthermore, the behavior of HPQ with Hg~(2+) in the solution was also investigated, and the result shows that HPQ was found to have excellent fluorescent selectivity for Hg~(2+) over many other metal ions(Li~+, K~+, Na~+, Sr~+, Ca~(2+), Mg~(2+), Mn~(2+), Fe~(3+), Ni~(2+), Co~(2+), Cu~(2+), Zn~(2+),Cd~(2+), Pb~(2+), Al~(3+) and Cr~(3+)) based on the intermolecular charge-transfer mechanism, which makes HPQ a potential fluorescence sensor or probe for Hg~(2+).     

Coordination Modes of Polypyridyl Quinoxaline with Hg(Ⅱ),Pb(Ⅱ),Co(Ⅱ) and Mn(Ⅱ)

The interaction of metal ions(Hg~(2+),Pb~(2+),Co~(2+),Mn~(2+)) with polypyridyl quinoxaline ligand 2,3,6,7,10,ll-hexakis(2-pyridyl)dipyrazino[2,3-f:20,30-h]quinoxaline(HPDQ) was investigated,and four new complexes have been synthesized and characterized.Complex 1 exhibits a 0dimensional dual-core structure,2 is a one-dimensional chain structure based on a dual-core Pb unit,while 3 and 4 show a 0 dimensional single-core structural unit.Complex 1 is of monoclinic system,space group C2/c with a = 19.211(4),b = 23.896(5),c = 12.698(3) ?,β= 120.11(3)°,V= 5043.0(17)?~3,Z = 4,S = 1.053,F(000) = 2976,R~a = 0.0637 and wR~b = 0.1068(I 2σ(I)).Complex 2 adopts triclinic system,space group P1 with a = 10.370(2),b = 12.195(2),c = 21.033(4) ?,α = 80.87(3),β= 81.22(3),γ = 82.38(3)°,V= 2579.3(8) ?~3,Z = 2,S = 1.099,F(000) = 1328,R~a = 0.0609 and wR~b =0.1365(I 2σ(I)).Complex 3 is of monoclinic system,space group Cllc with a = 14.166(3),b =16.621(3),c = 20.248(4) ?,β = 92.18(3)°,V= 4764.0(16) ?~3,Z = 4,S = 1.005,F(000) = 2108,R~a =0.0589 and wR~b = 0.1332(I 2σ(I)).Complex 4 belongs to the monoclinic system,space group C2/c with a = 14.404(3),b = 16.626(3),c = 20.346(4) ?,β = 92.43(3)°,V= 4868.2(17) ?~3,Z = 4,S= 1.068,F(000) = 2108,R~a = 0.0833 and wR~b = 0.1591(I 2σ(I)).Furthermore,the behavior of HPDQ with Hg~(2+),Pb~(2+),Co~(2+) and Mn~(2+) in the solution was also investigated,and the result shows after the metal ions were added respectively,the emission of all solutions shows fluorescence quenching and has a red shift compared with that of the HPDQ ligand.     

Syntheses and Crystal Structures of Hg(Ⅱ) and Ag(Ⅰ) Complexes Containing 2-Acetylpyridine-paminobenzoylhydrazone Ligand

The two complexes [HgI_2L](DMF)(1) and [AgL_2](ClO_4)(CH_3CN)(2) were synthesized from the reaction of Schiff base ligand(2-acetylpyridine-p-aminobenzoylhydrazone)(L) with HgI_2 or AgClO_4 respectively. The compounds are characterized by ~1H NMR,FTIR and elemental analysis. The structures of the ligand and two complexes are measured via single-crystal X-ray diffraction. In these two complexes,the structures are both distorted triangular bipyramids with five-coordinated centers.     

Syntheses,Crystal Structures and DNA-binding Properties of Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) Complexes Containing Imidazolium Derivatives

Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) complexes(1~4) based on 2-(2-pyridyl)benzimidazole(pbm) and 4,4'-oxybisbenzoic acid(H2odc) were synthesized. The formulas of these complexes are [Cd(pbm)(odc)2](1), [Co(pbm)(odc)2](2), [Cu(pbm)(odc)2](3) and [Zn(pbm)(odc)2](4) confirmed by single-crystal X-ray diffraction analysis, which shows that complexes 1, 2 and 4 belong to monoclinic system with space group P21/n, while complex 3 belongs to monoclinic system with space group P21/c. The binding properties of complexes 1~4 with CT-DNA are evaluated by ultraviolet spectrum, fluorescence spectra and viscosity measurements. The results indicate that complexes 1~4 have strong interaction with CT-DNA binding. These complexes exhibit an electrostatic or groove mode in respect of binding with DNA, which can effectively destroy DNA. And this binding mode may be applied to the interaction between the complexes and cancer cell DNA. Therefore, we hope to provide a theoretical and scientific basis for the research of anti-cancer drugs.     

Crystal Structure and Spectroscopic Analysis of Polypyridyl Quinoxaline with Ce(Ⅲ) and Nd(Ⅲ)

Two high coordination crystals were obtained by the interaction of Ce~(3+) and Nd~(3+) with polypyridyl quinoxaline ligand 2,3,6,7,10,11-hexakis(2-pyridyl)dipyrazino[2,3-f:20,30-h]quinoxaline(HPDQ), and they were characterized. Complex 1 exhibits a 0 dimensional three-nuclear structure, with the three Ce(Ⅲ) atoms being ten-, eleven- and twelve-coordinated. Complex 2 is a 0 dimensional dual-core structure and the Nd(Ⅲ) atom is ten-coordinated. Complex 1 is of monoclinic system, space group P2/c with a = 16.850(3), b = 16.617(3), c = 24.017(5) ?, β = 100.94(3)o, V = 6602(2) ?~3, Z = 4, S = 1.062, F(000) = 3372, R = 0.0504 and wR = 0.1463(I 2σ(I)). Complex 2 adopts a monoclinic system, space group C2/c with a = 25.795(5), b = 20.166(4), c = 13.059(3) ?, β = 112.29(3)°, V = 6286(2) ?~3, Z = 4, S = 1.004, F(000) = 2664, R = 0.0663 and wR = 0.1821(I 2σ(I)). Furthermore, the behaviors of HPDQ with Ce~(3+) and Nd~(3+) in the solution are also investigated. After the Ce~(3+) is added, the ultraviolet absorption of the solution is enhanced with a red shift compared with that of the HPDQ ligand. While after adding Nd~(3+), the ultraviolet absorption of the solution is weakened, and it has a red shift which is the same as Ce~(3+). However, after the respective addition of metal ions, the emission of all solutions is quenched and has a red shift compared with that of the HPDQ ligand.     

Crystal Structures of Cu(Ⅰ) and Cu(Ⅱ) Complexes of Tris(N-n-propylbenzimidazol-2-ylmethyl)amine

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Crystal Structures and DNA Binding Properties of 2-Naphthoxyacetic Acid Cu(Ⅱ) Complexes

Two new copper complexes based on 2-naphthoxyacetic acid ligand, namely [Cu(L)_2(CH_3CN)]_2(1) and [Cu(L)(1,10-phen)_2](2), where L = 2-naphthoxyacetic acid and 1,10-phen = 1,10-phenanthroline, were obtained by hydrothermal reaction and characterized by single-crystal X-ray diffraction. The binuclear complex 1 and mononuclear complex 2 belong to space group C2/c and P■, respectively. The binding properties of the two compounds with ct-DNA were investigated by UV-Vis and fluorescence spectra. The two compounds could bind with ct-DNA through interactions. Compound 2 displays stronger binding ability in the reaction with ct-DNA.     

Synthesis,Crystal Structure and Spectroscopic Properties of Zn(Ⅱ) with N-carbamylglutamate Ligand

Zn C6H8N2O5.H2O(NCGZn) has been synthesized, and its functional groups present in the title compound were confirmed by elemental analysis, TG and IR spectral studies. Meanwhile, the crystal of NCGZn was obtained by slow evaporation of a saturated aqueous solution at room temperature and confirmed by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P21 with a = 5.03220(1), b = 13.3747(4), c = 12.9944(4) , β = 92.987(2)o, V = 873.39(4) 3, Z = 2, C12H20N4O12Zn2, Mr = 543.10, Dc = 2.065 g/cm3, F(000) = 552, μ(Mo Ka) = 2.826 mm-1, R = 0.0422 and w R = 0.1142. In NCGZn, Zn(1) and the symmetry formed Zn(1) ions are connected by five atoms from four NCG-2H anions and a water molecule. A NCG ligand has two carboxylate groups, one connecting a Zn ion, and the other bridgiong two Zn ions. The NCG ligand bridges four Zn ions through the amino group and two carboxylate groups with a water molecule to yield a 3D coordination polymer structure with hydrogen bonds.     

Synthesis and Properties of a Heteronuclear Ag(Ⅰ)/Ni(Ⅱ) Complex

A complex, Ni (en)2 Ag3 (CN) 5 (en = ethylenediamine), was obtained through the reaction of [Ag (CN) 2] -units with Ni Ⅱ -diamine cation [Ni (en)2] 2 , and the structure was determined by single crystal X-ray diffraction. It is indicated that the complex has a 3D architecture through the silver-silver interactions and the bridging cyano groups. This complex displays interesting luminescent properties caused by argentophilicity at room temperature in solid state.     

Competitive bulk liquid membrane transport of Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ag(Ⅰ),Cu(Ⅱ)and Mn(Ⅱ),cations using 2,2'-dithio(bis)benzothiazole as carrier

A series of competitive metal-ion transport experiments has been performed.Each involved transport from an aqueous source phase across an organic membrane phase into an aqueous receiving phase.The source phase contained equimolar concentration of Co（Ⅱ）,Ni（Ⅱ）,Zn（Ⅱ）,Cd（Ⅱ）,Ag（Ⅰ）,Cu（Ⅱ） and Mn（Ⅱ） metal cations.The transport experiments of metal cations were carried out by 2,2’-dithio（bis）benzothiazole（DTB） in chloroform（CHCl₃）.The source phase being buffered at range pH of 4-6.5 and receiving phase being buffered at pH 3.The obtained results show that the selectivity and the efficiency of Ag（I） transport from aqueous solutions are observed in this investigation.The effect of concentration of palmitic acid in the transport efficiency of Ag（Ⅰ） ion was also conformed.     

Syntheses,Crystal Structures and DNA-binding Properties of Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) Compounds Containing Thiazole Derivatives

Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1～3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) have been determined by single-crystal X-ray diffraction analysis, which shows that all the three complexes belong to monoclinic system with space group P21/c. Time-dependent density functional theory(TD-DFT) calculation is performed on a reference structure of compound 3. The excited electrons mainly localized at the π* of ligand 2-(2-pyridyl)benzothiazole, which will be convenient for them to bind with the DNA reacting sites. Fluorescence spectroscopy, ultraviolet(UV) spectroscopy and viscosity were used to characterize the interaction of the compounds with Calf thymus DNA(CT-DNA). The results indicate that compounds 1～3 bind to CT-DNA and have a strong interaction with DNA. The compounds can probably bind to CT-DNA via a non-intercalative mode as concluded by studying the viscosity of a DNA solution in the presence of the compounds. This combination can effectively break DNA, which speculates that these three compounds may interact with the cancer cell DNA in this binding mode, thereby damaging the cancer cells.     

Syntheses,Structures,and Photoluminescent Properties of Two Zn(Ⅱ) Coordination Polymers with Helical Chains Structures

Two novel coordination polymers with helical chains, {[Zn(L)(H2O)]?H2O}n(1) and {[Zn(L)(p-bix)]?3.5H2O}n(2), where H2 L = 5-(4-hydroxypyridinium-1-ylmethyl) isophthalic acid and p-bix = 1,4-bis(imidazol-1-ylmethyl)benzene, have been hydrothermally synthesized, and charac-terized by elemental analysis, powder X-ray diffraction(PXRD), IR, thermal gravimetric analyses(TGA) and also by single-crystal X-ray diffraction. Both complexes 1 and 2 crystallize inmonoclinic, space group P21/c. Compound 1 displays a two-dimensional(2D) structure with two distinct types of helical chains; 2 shows a layered coordination polymer with two types of helical chains and features an interesting 2D→3D interdigitated architecture. Meanwhile, the luminescent properties of 1 and 2 have also been investigated in detail.     

Structures and Properties of Two Pillared-layer Mn(Ⅱ) MOFs with 5-Ethyl-pyridine-2,3-dicarboxylate

The reaction of Mn(OAc)2·4 H2 O, 5-ethyl-pyridine-2,3-dicarboxylic acid(H2 epda) and 4,4?-bipyridine(4,4?-bipy)/4,4?-bis(imidazolyl)biphenyl)(bibp) under hydrothermal conditions produced two new manganese(Ⅱ) MOFs [Mn(epda)(4,4?-bipy)1/2](1) and [Mn(epda)(bibp)1/2](2), which were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analyses, and single-crystal X-ray diffraction. The structures of complexes 1 and 2 are similar. In 1, the adjacent Mn(Ⅱ) ions are connected by epda dianion to generate a 2 D(4,4) grid layer, and such 2 D layers are further connected via bibp ligand to form another layer, forming a 2 D pillared-layer. Topologically, the Mn atoms as the node are bridged by the edpa anions and bibp ligands to form a uninodal 5-connected network topology. The magnetic properties of 1 and 2 have also been-investigated, and the exchange interctions were –1.39 and –1.05 cm1, respectively. According to the crystal structures, compounds 1 and 2 were carried out by using hybrid DFT methods at the B3 LYP/6-31 G(d) level. The DFT-BS approach was applied to study the magnetic coupling behaviors for 1 and 2. The result reveals that the calculated exchange coupling constants J were in good agreement with the experimental data.     

Cu(Ⅰ) and Cu (Ⅱ) helical complexes formed with oligobipyridine ligand

A new asymmetric oligobipyridine ligand, 1-(5'-methyl-2, 2'-bipyridin-5-yl)-2-(6'-methyl-2, 2'-bipyridin-6-yl)ethane (L), in which the bipyridine units are bridged by CH_2CH_2 at 5, 6'-position has been synthesized. The ligand L reacts with Cu(Ⅰ) and Cu(Ⅱ) ions giving double-stranded helical complexes [Cu_2~ⅠL_2] (ClO_4)_2·Et_2O (1) and [Cu_2~ⅡL_2 (OH) (H_2O)][ClO_4]_3(2), respectively. Complexes 1 and 2 were characterized by X-ray diffraction analyses, ES-MS, ESR and cyclic voltammetry, etc. Differing from the oligobipyridine ligands bridged by CH_2CH_2 at 6,6'-or 5,5'-position, the ligand L not only forms a double-stranded helicate with Cu(Ⅰ) ion, but also gives a double-stranded helicate with Cu(Ⅱ) ion. The results show that the linkage mode of the spacer group to the bipyridine units exerts a great impact on the formation of helix.     

Synthesis and Properties of u-Oxamido Heterobinuclear Cu(Ⅱ)-Co(Ⅱ) Complexes

Three heterobinuclear complexes were synthesized, namely [Cu (oxpn) Co (L)2] (ClO4)2·xH2O(L= 2,2'-bipyridyl(bpy), 1,10-phenanthroline(phen) , and 5-nitro-1, 10-phenanthroline (NO2-phen)), where oxpn represents N, N'-bis(3-aminopropyl) oxam-ido. Based on 1R, elemental analysis, conductivity measurement and electronic spectra, these complexes were characterized by an extended oxamido-bridged structure with Cu(Ⅱ) in a planar environment and Co(Ⅱ) in a octahedral environment. The symmetry of the cation is very close to C2v.The complexes were also characterized with variable temperature (4~300K) magnetic susceptibility, and the data were fit for the susceptibility equation derived from spin Hamilton, H= -2JS1.S2-DSx12 by least square strategy. The exchange integral, J, was found to be -22.36 cm-1 (for bpy);-15.45 cm-1 (for phen); -19. 10cm-1(for NO2-phen), indicating that there is a weak antiferromagnetic spin-exchange interaction between the metal ions.     

Synthesis and Study of Spectroscopic Properties of Imidazole Porphyrin and Its Zn(Ⅱ) Complex

A novel sensitizer with imidazole zinc porphyrin as electron donor has been synthesized. The structure has been characterized by UV-Vis, elemental analyses and 1 H NMR.UV-Vis and fluorescence spectra show that it has good light absorbing properties in the range of visible light and suggests that it has potential applications in dye-sensitized solar cells.     

Spectroscopic Studies on Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ) Complexes with 4,4'-Bipyridine

Fourier-transform infrared(FTIR),Raman and ultraviolet-visible spectra of 4,4'-bipyridine and its me-tal-organic coordination compounds synthesized from 4,4'-bipyridine and nitrate of Co(Ⅱ),Ni(Ⅱ) and Zn(Ⅱ) were measured and analyzed,respectively.The main FTIR and Raman bands were assigned in detail.The relationship between these characteristic bands and the structure of ligands and coordination compounds were discussed.